Internal pipe wrench



Oct. 7, 1969 A. P. sABo INTERNAL PIPE WRENCH 2 Sheets-Sheet 1 Filed March 20, 1967 I NYE NTOR.

ANTHONY F? SABO Oct. 7, 1969 A. P. SABO 3,

INTERNAL PIPE WRENCH Filed March 20, 1967 v 2 Sheets-Sheet 2 I INVENTOR.

ANTHONY P. SABO United States Patent ABSTRACT OF THE DISCLOSURE The specification discloses a torque-transmitting engagement means adapted to cooperate with a conventional pipe wrench, or other conventional torque-applying tool, which engages the exterior of a portion of the torquetransmitting engagement means of the present invention in a manner such that the combination of the torquetransmitting engagement means and the pipe wrench may be said to effectively comprise an internal pipe wrench capable of applying torque to the interior of an exteriorly threaded open end of a pipe rather than to the exterior thereof in the conventional manner provided by applying the pipe wrench directly to the exterior of the open end of the pipe in a conventional torque-applying manner. This prevents physical damage from occurring to the exterior of the threaded open end of the pipe, since the pipe wrench does not directly engage the threaded exterior open end of the pipe when torque is applied to the pipe.

Generally speaking, the present invention relates to the hand tool art and, more particularly, to what might be termed a torque-transmitting engagement means for internally engaging a pipe so that torque may be effectively applied to the pipe by a pipe wrench or the like applied to a portion of the exterior of the apparatus of the present invention rather than to the exterior of the pipe as is normally done when torque is to be applied to a pipe by using a conventional pipe wrench. In other words, rather than to apply torque directly to the exterior of a pipe by applying a conventional pipe wrench thereto, the novel apparatus of the present invention acts as an effective intermediary or coupling means between the conventional pipe wrench and the pipe to which torque is to be applied, and does so in a manner such that the final application of torque to the pipe is not by way of exterior contact therewith but is by way of interior contact therewith. This has certain advantages in that it prevents any marring or scarring of the exterior of the pipe by the conventionally serrated jaws of a conventional pipe wrench and where the pipe in question to which torque is to be applied comprises a plumbing fitting or plated or coated pipe, or the like, which is normally in view, this may be of considerable importance since it is desirable that any such exterior marking or scarring of the plated plumbing fitting or plated pipe be minimized or completely prevented if possible, and precisely this desirable result is achieved through the use of the novel torque-transmitting engagement means of the present invention which produces absolutely no exterior marring or scarring of the pipe to which torque is to be applied by a pipe wrench.

Also, it should be noted that in most cases where a pipe is to have torque applied thereto and only a short length thereof projects from the wall or other surface and virtually the entire projecting length is exteriorly threaded for engagement with some other fitting or structure, it will be found that applying torque exteriorly to the pipe in a conventional manner by a conventional pipe wrench will seriously damage the exterior threads adjacent to the end of the pipe, and this type of damage, especially where a very large amount of torque is required, may damage the exterior pipe threads to such an M CC extent that they will be virtually unusable for threaded engagement purposes subsequently, and the pipe end may have to be rethreaded.

The novel torque-transmitting engagement means of the present invention completely overcomes the abovernentioned prior art disadvantage because the pipe wrench does not engage the exterior threads of the pipe at all when torque is applied to the pipe through the use of the novel apparatus of the present invention, and thus no damage is done to the exterior pipe threads at all and yet as much torque as is required can be easily applied to the pipe end through the use of the noval apparatus of the present invention.

Additionally, it should be noted that when an open pipe end is very nearly flush mounted in a wall or other surrounding medium so that the pipe end does not protrude therefrom to any substantial degree adequate for exterior engagement by a conventional pipe wrench, it will be found virtually impossible to apply torque to the pipe with a conventional pipe Wrench unless a portion of the wall or other medium in which the open pipe end is mounted is actually dug away from the pipe end so as to expose a substantial length thereof so that a pipe wrench or other exterior torque-applying tool can be engaged with the newly exposed pipe end. This type of situation is frequently encountered in plumbing repair and new installation work in pre-existing buildings, and usually re quires that a wall then be replastered in order to fill in the portion of the wall surface which had to be dug out in order to expose a substantial length of pipe end so that a pipe wrench or other exterior torque-applying tool could be engaged therewith.

The last above mentioned prior art disadvantage and problem is completely eliminated and overcome if only a very short exteriorly threaded length of the pipe end is exposedtoo short a length for effective exterior engagement by a conventional pipe wrench in a conventional manner for applying substantial amounts of torque thereto without major damage being done to the exteriorly threaded pipe end-in and through the use of the novel torque-transmitting engagement means of the present invention because of the fact that it may be readily engaged within the open end of a pipe which is very nearly flush mounted in a wall or other surrounding medium, and without requiring that a substantial portion of the wall or surrounding medium be dug away in order to expose a substantial length of the exterior of the pipe in the undesirable prior art manner mentioned above. This is so because the novel torque-transmitting engagement means of the present invention can be engaged with the pipe end if only a very short exteriorly threaded end portion thereof is exposed. If the open pipe end is completely flush mounted in the wall, it will be found that only a very small amount of the material of the wall need be removed around the flush mounted pipe end in order to expose a very short exteriorly threaded end thereof, or a very short end which can be exteriorly threaded after such exposure.

Additionally, it should be noted that an open pipe end very nearly flush mounted in the wall as mentioned above, and which has an exteriorly threaded end, will normally have either a portion of the exteriorly threaded end protruding from the wall surface or will have an annular portion of the wall removed therearound so as to provide access for the engagement with the exteriorly threaded pipe end of a corresponding interiorly threaded pipe end coupling element, elbow, or plumbing fitting, and where such a small clearance region is provided, it will be found very difficult to exteriorly grasp the pipe end with a conventional pipe wrench for applying torque thereto because of the geometry of the annular small clearance region. This problem is also completel met and overcome by the novel torque-transmitting engagement means of the present invention, which can easily engage an open pipe end substantially flush mounted in the wall if even a very small annular clearance opening or recess is provided in the wall around a short length of the exteriorly threaded end thereof.

With the above points in mind, it is an object of the present invention to provide a novel torque-transmitting engagement means for internally engaging an exteriorly threaded open end of a pipe in a manner requiring a minimum clearance region with respect to the exterior of the open end of the pipe and in a manner which does not directly apply a pipe wrench or other torque-applying tool to the exterior end of the pipe and thus does no physical damage thereto as a result of the application of large amounts of torque to the pipe from a torque-transmitting tool, such as a pipe wrench or the like, applied to the novel torque-transmitting engagement means of the present invention and from same to the interior of the open pipe end.

It is a further object of the present invention to provide what might be termed an effective internal pipe wrench, comprising apparatus as referred to in the preceding object and which has any or all of the advantages referred to herein, generally and/ or specifically, and individually or in combination, and which is of extremely inexpensive, foolproof, easy-to-use construction, employing, in certain forms of the invention, several virtually standard type plumbing items of extremely low cost, whereby to be conducive to widespread use of the present invention.

Further objects are implicit in the detailed description which follows hereinafter (which is to be considered as exemplary of, but not specifically limiting, the present invention), and said objects will be apparent to persons skilled in the art after a careful study of the detailed description which follows hereinafter, and all such implicit objects are intended to be included and comprehended herein as fully as if detailed with great particularity herein.

For the purpose of clarifying the nature of the present invention, several exemplary embodiments of the invention are illustrated in the hereinbelow-described figures of the accompanying drawings and are described in detail hereinafter.

FIG. 1 is an exploded, fragmentary, partially broken away perspective view of one exemplary embodiment of the invention showing certain of the various elements thereof in sectional form, taken substantially on a central, longitudinal axial plane thereof and showing other elements thereof in non-sectional form.

FIG. 2 is an assembled, engaged, operative view of the apparatus of FIG. 1 shown in sectional form on a longitudinal, central plane thereof and with the apparatus in torque-transmitting, engaged relationship with respect to the open end of a pipe shown fragmentarily and also in longitudinal, central plane sectional form with respect to the engaged open end part thereof. This view also shows fragmentarily the engagement of a conventional pipe Wrench with respect to the exterior of the coupling means.

FIG. 3 is a top plan view of the exemplary tapered insertion engagement member of the first form of the invention shown by itself and with all other portions of the apparatus removed.

FIG. 4 illustrates a modified form of the means for rotatively immobilizing the tapered insertion engagement member with respect to the tubular coupling member and shows said elements in fragmentary, exploded, perspective form.

FIG. 5 is a view generally similar to FIG. 4 but illustrates a further slight modification of the invention wherein the conically arranged engagement surface means differs from the first form of the invention shown in FIGS. 13 and the rotative movement-immobilizing or key means differs from said first form of the invention and also from the slight modification thereof illustrated in FIG. 4.

FIG. 6 is a central plane sectional view similar to FIG. 2, but illustrates a form of the invention much like the FIG. 5 form of the invention, but having a further slight modification of the rotative movement-immobilizing or key means.

FIG. 6A is a cross-sectional view taken substantially on the plane indicated by the arrows 6A6A of FIG. 6.

FIG. 7 is a fragmentary, perspective view of a slightly modified tapered insertion engagement member having a slightly different forwardly tapered pipe-end-engaging surface means and also a slightly different male element portion of a modified relative rotative movement-immobilizing key means adapted to keyingly cooperate with a similarly shaped, apertured female receiving element or portion thereof adapted to be carried by a modified tubular coupling member (not shown in this figure).

FIG. 8 is a view generally similar to FIG. 7 but illustrates a serrated type of forwardly tapered pipe-end-engaging surface means and also illustrates a slightly different male element portion of a modified relative rotative-movement-immobilizing key means adapted to keyingly cooperate with a similarly shaped, apertured female receiving element or portion thereof adapted to be carried by a modified tubular coupling member (not shown in this figure).

FIG. 9 is a view similar to FIG. 7 and to FIG. 8 and illustrates a serrated type of tapered forward pipe-endengaging surface means similar to that shown in FIG. 8 but also illustrates a slightly different male element portion (generally similar to that shown in FIG. 7) of a modified relative movement-immobilizing key means adapted to keyingly coopearte with a similarly shaped, apertured female receiving element or portion thereof adapted to be carried by a modified tubular coupling member (not shown in this figure).

Generally speaking, the torque-transmitting engagement means of the present invention may be said to comprise a tapered insertion nipple or engagement member, such as is generally designated by the reference numeral 20 in the first exemplary form of the invention, and which has a forward, effectively tapered, effectively frusto-conically shaped engagement portion 22 exteriorly provided with what might be termed exteriorly frictional engagement surface means 24, which in the exemplary first form of the invention comprises what might be considered to be a very coarsely serrated or toothed engagement surface means having what amounts to only four conically positioned exterior serrations or tooth'portions 26 comprising those portions lying outside of the effectively circular-in-horizontal section, basically frusto conically shaped engagement member 22 best shown in broken lines in FIG. 3.

It should be clearly understood that the actual appearance of the forward engagement sufface means portion 24 is that of a prism rather than a cone, but this prismlike appearance of the forward engagement surface means portion 24 may be said to effectively arise from the combination of a basically frusto-conically shaped engagement member 22 provided with four exterior serrations, teeth, or ribs 26, which together with the basic frustoconically shaped forward engagement portion 22, provides the prism-like shape of the combination thereof including both the element 22 and the four ribs 26 which together define the effectively serrated, toother, frictional engagement surface means generally designated at 24.

Incidentally, it should be noted that the engagement surface means, generally designated at 24, is merely'an exemplary one of many different non-round shapes which effectively provide exterior ribs, teeth, or serrations which are positioned in conically forwardly converging, relative locations and any of such arrangements may be employed in lieu of the specific prism-like shape of said engagement surface means 24 illustrated in the first form of theengagement, and several such alternative arrangemerits are illustrated in FIGS. 7, 8, and 9, and an alternate arrangement which is basically the same in principle although at first glance it does not appear to be the same as illustrated in FIG. 5, and in this form the frictional engagement surface means providing a plurality of exterior serrations, teeth, or ribs in forwardly converging, conically positioned arrangement, takes the form of a larger number of such serrations positioned around the effective f'rusto-conical forwardly directed engagement member. However, all of said modifications of the forward engagement portion of the tapered insertion nipple or engagement member 20 are functionally equivalent and effectively comprise a frusto-conically forwardly tapered engagement portion such as that shown at 22, exteriorly provided with serration, tooth, or rib means, or the like, which provide an exteriorv frictional surface means, such as that shown at 24, which is non-round in cross-section at any particular point so as to be capable of biting into and positively fIictionally engaging the circular inner end edge part 28 of an open pipe end, generally indicated at 30, for applying torque thereto in a. manner such as will be described in greater detail hereinafter.'

The invention also includes coupling means for forcibly coupling the insertion nipple engagement member 20 with respect to the open pipe end 30 in a manner such as to be capable of transmitting torque therethrough from a pipe wrench or other torque-applying tool, shown fragmentarily at 31 in FIG. 2, adapted to be forcibly positively engaged with the exterior of the coupling means, through the coupling means, the tapered insertion nipple or engagement member 20 to the open pipe end 30 by way of interior engagement with the inner end edge 28 of the open pipe end 30.

In the exemplary first form of the invention illustrated, said coupling means is generally designated by the reference numeral 32 and comprises an internally threaded short length of pipe 34 having a rear openend 36 and a front or forward open end 38 and provided with the interior threads 40 along the hollow bore or interior 42 thereof "adapted to threadedly engage the exterior threads 43 of the open pipe end 30 in the manner best shown in FIG. 2 when the coupling means 32 is to be fastened thereonto so that the insertion nipple engagement member 20 may be effectively internally coupled to the inner front edge 28 of the open pipe end 30 so that torque may be applied to the open pipe end 30 in the manner best illustrated in FIG. 2.

The above-mentioned coupling .means, generally designated at 32, also comprises an exteriorly threaded force applying plug means which, in the exemplary first version of the invention, takes the form of a cylindrical follower plug element 44 provided with exterior threads 46 of a size and pitch such as to be capable of threaded engagement within the interior threads 40 within the hollow interior or bore 42 of the tubular coupling member or pipe 34 adjacent to the rear open end 36 thereof in a manner such as is clearly shown in FIG. 2.

The exteriorly threaded follower plug element 44 has a flat, forward abutment surface 48 which is adapted to effectively apply forwardly directed force with respect to a rear abuttable force-receiving surface 50 at'the rear end of a non-tapered main body portion 52 of the previously mentioned tapered insertion nipple o-r engagement member 20. In the example illustrated, a washer 54 is adapted to be positioned between the force-applying abutment surface 48 at the forward end of the follower plug element 44 and the abuttable force-receiving surface 50 at the rear end of the nipple or engagement member 20. This may have the effect of acting as a coupling element between the surfaces 48 and 50, particularly in view of the fact that the surface 48 rotates when the follower plug element 44 is threaded forwardly into the interior 6 threads 40 within the hollow interior or bore 42 of the tubular coupling member 34 while the abuttable surface 50 of the insertion nipple or engagement member 20 does not rotate for reasons which will be explained hereinafter.

The follower plug element 44 is provided with a rearwardly projecting non-round torque-transmission tool engagement portion 56 which is adapted to be engaged in a "torque-transmitting manner by a torque-transmitting tool, such as a pipe wrench, socket wrench, or the like, when the exteriorly threaded follower plug element 44 is forcibly forwardly threadedly advanced within the interior threads 40 of the tubular coupling member 34 for positively forwardly moving the insertion nipple or engag'ement member 20 into locking engagement within the interior end edge 28 of the open pipe end 30.

The apparatus of the invention, in one preferred form thereof, may be said to include relative rotative movement-immobilizing means for effectively coupling the engagement member 20 to the tubular coupling member 34 in a manner which positively prevents relative rotative movement thereof when the serrations, teeth, or ribs 26 of the frictional engagement serration, tooth, orrib means 24 are jammed into locking engagement with the inner forward edge 28 of the open pipe end 30 in the manner best shown in FIG. 2. This is so that torque may be applied to the exterior torque engagement surface means 58 of the tubular coupling member 34 by applying a pipe wrench 31 or other torque-applying tool thereto for transmitting torque through the assembled structure best shown in FIG. 2 to the interior end edge 28 of the open pipe end 30 which would not occur if relative rotation could occur between the insertion nipple or engagement member 20 and the tubular coupling member 34.

In the exemplary first form of the invention illustrate-d, said relative rotative movement-immobilizing means effectively comprises the exterior threads 46, the interior threads 40, the abutment and abuttable surfaces 48 and 50, and the washer 54 positioned therebetween, all of which are forcibly jammed together in positive frictional locking engagement when the apparatus is in the engaged relationship best shown in FIG. 2 with the exteriorly threaded follower plug element 44 forcibly threadedly forwardly advanced as far as can be accomplished by the application of a very substantial amount of torque to the torque-transmission tool engagement portion 56 at the rear end of the follower plug element 44. When all of said engaged surfaces, effectively comprising said relative rotative movement-immobilizing means, are in said forcibly jammed together relationship as clearly shown in FIG. 2, they are capable of transmitting torque from a pipe wrench 31 applied to the exterior surface 58 of the tubular coupling member 34 through the jammed assembly of follower plug element 44, tapered insertion nipple or engagement member 20, optional washer 54 positioned therebetween, and through the conically arranged serration, tooth, or rib means 24 to the forward interior edge 28 of the open pipe end 30.

FIG. 4 illustrates a modification of the first exemplary form of the invention, and similar parts are indicated by similar reference numerals, followed by the letter a,

however.

1 In the FIG. 4 modification, the only change from the first form of the invention is the fact that the lower or main body portion 52a of the tapered insertion nipple or engagement mem ber 20a is of non-round configuration and may be said to effectively comprise a non-round aperture abutment means 60 comprising projecting ribs, serrations, tooth means, or any other non-round structural elements which may be similar to the previously discussed and described, forwardly conically arranged ser-' rations, tooth means, ribs, or the like 26, comprising the frictional engagement surface means 24 of the first form' of the invention, or any of the modifications illustrated in FIGS. 5-9.

An intermediate portion of the interior hollow region or bore 42a of the tubular coupling member 34a is provided with a similarly shaped non-round aperture-defining means 62 adapted to receive the non-round aperture abutment means 60 in a relative rotative movement-immobilizing manner, and thus the elements 60 and 62 may be said to effectively comprise one form of relative rotative movement-immobilizing key means, which is generally designated by the reference numeral 64, which positively prevents relative rotation of the tubular coupling member 34a with respect to the insertion nipple or engagement member 20a.

FIG. illustrates a further modification of the invention and, therefore, parts structurally or functionally similar to those of previously described forms of the invention are designated by similar reference numerals, followed by the letter b, however.

In the FIG. 5 modification of the invention, it will be noted that the major change is the fact that the conically arranged frictional engagement surface means 24b of the insertion nipple or engagement member 201) comprises multiple serrations 26b and that the relative rotative movement-immobilizing key means, generally indicated at 64b, comprises two-element mating projecting means and receiving groove means which, in the example illustrated, has the projecting means carried at the rear of the insertion engagement member 20b as indicated at 60b with the receiving groove means 62b being carried within the hollow bore 42b of the tubular coupling member 34b and cutting through the interior threads 4% thereof.

In other words, the two-element mating projecting means and receiving groove means, including the elements 60b and 62b, which together comprise the relative rotative movement-immobilizing key means 6417, provide longitudinally slidable but relatively non-rotatively engaged relationship thereof and of the corresponding insertion nipple or engagement member 20b and the tubular coupling member 34b in a manner structurally different from but fully equivalent to the corresponding showing of the form of the invention illustrated in FIG. 4. Otherwise, this modification of the invention is similar to said previously described form of the invention illustrated in FIG. 4.

FIG. 6 illustrates a further slight modification of the invention very similar to the previously described form and, therefore, similar parts are designated by similar reference numerals, followed by the letter c, however.

The major difference of the FIG. 6 modification of the invention from the immediately previously described form of the invention is the fact that the serrations 24c on the cylindrical base part 520 of the insertion nipple or engagement member 200 are slightly larger in exterior diameter than the interior diameter of the interiorly threaded bore 42c of the tubular coupling member 340 and thus forcible insertion of said engagement member 200 within the slightly smaller diameter, interiorly threaded bore 420 of the tubular coupling member 340 will cause the largest diameter base portion serrations 24c to bite into or cut into and extend across the interior threads 400 within the tubular coupling member 340 and thus become non-rotatively locked with respect thereto.

The exterior diameter of the threaded follower plug element 44c is still of the proper diameter to engage the threads 40c and thus is slightly smaller in diameter than the largest diameter base serrations 24c carried by the insertion nipple or engagement member 200.

The arrangement operates or functions substantially the same as the immediately previously described form of the invention, with the largest diameter base serrations 24c at the rear of the engagement member 200 and the plurality of effective longitudinal grooves 62c forcibly formed thereby comprising the functional equivalent of the elements 60!) and 62b of the immediately previously described form of the invention and together effectively comprising a very slightly modified form of the relative rotative movement-immobilizing means previously described and in this case generally designated by the reference numeral 640.

As previously mentioned, the engagement surface means, indicated generally at 24, of the first form of the invention may assume a variety of non-round crosssectional configurations and also the non-round aperture abutment means as illustrated in the second form of the invention described hereinbefore (and the correspondingly shaped non-round aperture-defining means such as designated at 62 in the second form of the invention described in detail hereinbefore) may assume any of a great multiplicity of different non-round shapes capable of functioning in a torque-transmitting manner and a variety of such different non-round shapes with respect to the male elements just referred to are shown in FIGS. 7 through 9 and are designated by corresponding reference numerals, followed by successively different lower case reference letters beginning with reference letter d in the case of FIG. 7, and continuing through the letter in the case of FIG. 9. These are merely illustrative of certain of the permissible variations of said parts within the broad scope of the present invention and are not intended to comprise different species of the four different major species of the invention illustrated respectively in FIGS. 1-3, 4, 5, and 6.

It should be understood that the figures and the specific description thereof set forth in this application are for the purpose of illustrating the present invention and are not to be construed as limiting the present invention to the precise and detailed specific structure shown in the figures and specifically described hereinbefore. Rather, the real invention is intended to include substantially equivalent constructions embodying the basic teachings and inventive concept of the present invention.

I claim:

1 Torque-transmitting engagement means for internally engaging a pipe, comprising: a separate integral unitary tapered insertion engagement member exteriorly provided with conically positioned tapered engagement surface means having a reduced diameter tapered forward end adapted to be inserted into the interior of an open pipe end for torque-transmitting rotative engagement with an inner end surface portion thereof, said conically positioned, tapered engagement surface means comprising a plurality of conically positioned projecting effective engagement tooth means; coupling means physically separate and discrete from said separate integral unitary tapered insertion engagement member for forcibly adjustably coupling said tapered insertion engagement member with respect to an open pipe end and controllably operable in a manner positively forcing said tapered engagement surface means of said tapered insertion engagement member into the interior of an open pipe end engaged by said coupling means into positive torque transmitting engagement relative thereto, said coupling means comprising an integral unitary internally threaded short length of pipe having open opposite ends and an interior bore extending through the length of said pipe and connecting said open opposite ends and comprising a tubular coupling member adapted to receive said tapered insertion engagement member therein and provided with a physically separate and discrete exteriorly threaded force-applying plug means threadedly engageable within the interiorly threaded coupling member for forcing said tapered insertion engagement member forwardly through the threaded interior of said coupling member and into forcible jammed torquetransmitting engagement with an inside end portion of the open end of a pipe adapted to have an exteriorly threaded portion thereof threadedly engaged within the opposite interiorly threaded end of said coupling member in opposition to a forward direction of movement of said tapered engagement member, said physically separate and discrete exteriorly threaded force-applying plug means comprising an exteriorly threaded integral follower plug element physically separate and discrete from said separate tapered insertion engagement member and adapted to be positioned in interior relatively rotatable threaded engagement Within a rear end portion of said bore of said interiorly threaded coupling member for relative rotation with respect to a flat abutment rear end of said non-rotatable but longitudinally movable physically separate tapered insertion engagement member for forcing said physically separate tapered insertion engagement member forwardly in response to said relative rotation and forward advancement of said physically separate and discrete follower plug element within the rear interiorly threaded end portion of said bore of said tubular coupling member, said physically separate and discrete exteriorly threaded follower plug element being provided with a rearwardly projecting non-round, torquetransmission, tool engagement portion adapted to be engaged in a torque-transmitting manner by a torqueapplying tool; and effective relative rotative movementimmobilizing means effectively coupling the exterior of said physically separate forwardly tapered engagement member to the interior of the bore of said integral unitary tubular coupling member in a manner preventing relative rotative movement thereof; said integral unitary interiorly threaded coupling member having an exterior tool engagement means engageable in a torquetransmitting manner by a torque-applying tool for positively transmitting torque through said coupling member, said relative movement immobilizing means, said physically separate tapered engagement member effectively coupled by said relative rotative movement-immobilizing means to said physically discrete coupling member carrying said tapered engagement member and, through the engagement surface means of said physically separate tapered engagement member to a pipe adapted to be forcibly frictionally engaged by said engagement surface means of said forwardly tapered engagement member when jammed against an open pipe end adapted to be threadedly inserted Within the opposite threaded end of said bore of said tubular coupling member.

2. Apparatus as defined in claim 1, wherein said plurality of conically positioned projecting effective engagement tooth means of said conically positioned, tapered engagement surface means comprises a plurality of conically arranged engagement serration means.

3. Apparatus as defined in claim 1, wherein said relative rotative movement-immobilizing means comprises relative rotative movement-immobilizing key means effectively coupling the exterior of said forwardly tapered engagement member to the interior of said tubular coupling member in a manner allowing relative longitudinal movement thereof but preventing relative rotative movement thereof.

4. Apparatus as defined in claim 3, wherein said relative rotative movement-immobilizing key means comprises non-round aperture-defining means positioned Within said coupling member and a correspondingly shaped non-round aperture abutment means carried by said forwardly tapered engagement member.

5. Apparatus as defined in claim 3, wherein said relative rotative movement-immobilizing key means comprises two-element mating projecting means and receiving groove means longitudinally slidably and relatively nonrotatably engaged, with one of the elements thereof carried by the interior of said threaded coupling member and with the other of the elements thereof carried by the exterior of said forwardly tapered engagement member.

6. Apparatus as defined in claim 3, wherein said rela- References Cited UNITED STATES PATENTS 456,860 7/1891 Spencer 2797 523,722 7/ 1894 Hall et a1. 2797 540,989 6/1895 Keyes 2797 619,553 2/1899 Fox 2797 JAMES L. JONES, JR., Primary Examiner US. Cl. X.R. 8l--53, 71 

